<script>
chrome.extension.onRequest.addListener(
  function(request, sender, sendResponse) {
    if (request.fetch == "khwords") {
      if (localStorage && localStorage["khwords"] != undefined) {
        sendResponse({khwords: localStorage["khwords"]});
      } else {
        sendResponse({});
      }
    } else {
      sendResponse({}); // snub them.
    }
  });
</script>  